Bead for pneumatic tire casings and method of making the same



Feb. 28, 1933. w, CLGEER 1,899,088

BEAD FOR PNEUMATIC TIRE CAS INGS AND METHOD OF MAKING THE SAME Filed June 27, 1925 //////jIIIIIIII/IIIIIIIIIAIlflll III/ll Patented Feb. 28, 1933 member?mo w omojfnsszeiton wo ms 35F?GOObRICHi"CQ1ii?ANY;{0F a j @1151)FORQPNEUMATIQTIREECKSINGS A D METHOD oriyraxnre THE SAME .i-zwkpplioatiomfiledi June mmmza zxsorial No." 399,63.

This invention. relates to rings employed-in the-manufacture opneumat1c tire zcasingsi and-ithasfor an, object to providean improved method ofcon'structing ahead, one .which shall permitthe eliminationrof certain operations now required for the building of a bead and which will materially out .down the ,time requiredgior other operations. A further object- =isto providean improved bead structure which shallbe simpler -andrmore economical to "manutacture: than beads now employed 'in. manufacturingpneumatic tire ame v In themanufactureofbeads ior casingspf the fclincher type heretofore it has been the j vpra cticeto form thebead bodyof a hard riibber 'stock, cover-thebead-body :with a rubber- V p i prepared byreacting crude rubher under the -ized fabrimisemi-cure the fahric oovered bead body; usually at 70-pounds steam pressurefor v3O minutes; bufi the semi-cured, coveredbead 1' Views showing the silcces'sive steps in constructing a Wire-contain ng bead according I to the-present invention; Fig. 10; is1asecti0n a1 View .off a modified 1 structure of the bead shown Fig. 9; and Eigsll, ligand 13i'arew5 sect onviews illustrating fs cc ssiv tepsin building up a f urth'er modified con The process of the Vpres'ent"invention'de pends for its successful"operation upon them "use :or a' thermoplastic composition which hasthe requisite hardness at normal temp'eratures'and yet maybe calenderd or tubed readily when. warmed, andffurther presents a surface to' which adhesiveswill bindfirmlyafis lprefer'ably employ a composition having as its :1 essential ingredient "certain c substances to give: a good cementing surface, pass. the bufi'ecl,lieacl through a rubber cementyevap- ,orateJ the solvent, cut to length-and: form a ring, and finally cover-the ring; with a rnb- .berized fabric strip having one edge extendingf for-Jan inch or more beyond-the bead to a form these-called flipper- Which gives tothe tire casing; an increased stiflfness contiguous to theIbeads. In the case of beads containing wire, a similar proceeding is involved in their fabrication.

- I am enabled. the .use of. special thermoplastic: compositions to construct a superior bead. and;atfthesame-time to eliminate the step ofrsemi-curing the bead andofbuifing the fabric'cover, when'the latter 'is. employed.

The thermoplastic composition also makes nc 10f 11W i l various isomer-Zin agents "f r ben; particularly compo r id c having the n al formula 'R :SO2+"X wherein R represents an organic 'radifcal or a 'hydroxy "group and represents a fhydr'oxy group or chlorine; and including organic-sulfonic acids, organic sulfonyl' chlorides 311(1n75 sulfuric-acid.

; Substances of this character-3'aredescribed in an application filed by1H5 L": Fisher;- Seri'al No. 7585099 now Patent No." 1,605,180

granted November '2; 1926 I have found the gtw *following tobe especially practicaland commercially satisfactory in theher'ein described possible-the omission entirely of the head I cover since the'composition itself offers a' good cementing surface.

' OftheaccompanyingdrawingFig, 1 is a diagrammatic view of one embodiment of the'= v apparatus employed in iorming'my new head structure Fig2-is asectionfof'thebead as it comes" from the embossing rol ls of the cale'nder -'Eig;" 3 is an elevation 1 of the bead ring ie spliced by a tape: winding ;-Fig.- 4 is asectiond of the'ibeadring ofiEig.'-: 3 after the flipper processes: "("1')'- the' reaction product of"'pphenol 'sulfonic l acid, 7 "-p'a-rtsby weight,

and rubber, 100-parts,when heated in atom-x1 or 'rea-ction'products iir- Which-"the p' phenol 'sulfonic acidis' replac'ed by any ofthefoland sulfuric. acid; 2' parts ;-or othersulfonic ac'ids and acid sulfonyl chlorides or mixtures pro'duct of v- 4 to 5 parts 'of concentrated sul= thereof, 5 to 9 parts. 2)=A similar reaction 'furie acid" -(.sp;:gr.f1.84) and crude rubber; 100

' partsywithiwhich is :m'ixed from 2sto'50zparts v of pine/car; :when heated in; a compact mass ,=has been applied-and'in condition :tobebuilt from 4 to 7 hours at 268 F. into a tire carcass; Figs. 5 0 9zare=sectional The above productsyhaveabeen foundiupondw 0.970110 1.005, and are freely plastic at'relatively low temperatures. The term-Thermo- 7 prene" has been applied in the trade to these.

products and is l ised inv the present specifica- 4 tion for brevity convenience of express1on. -v

In the preparation 6f composition a1 the bead body, I mix with the Thermoprene,

10 parts by weight, 50 to 60 parts of ground- Qvulcanized scrap, 10 "parts of mineral "rub-J ber'and parts of Dixie clay This compolsition calenders and'tubes satisfactorily and fornisin the finished tire casing'an uncured beadof satisfactory quality. A somewhat stronger bead. is formed where sulfur 1.5 parts and calciumoxide 5 parts are added to r the above compound, the added ingredients. 1 seryingto' cure or set the bead when the tire carcass is vulcanized. 'The above recipe is illustrative merely andl may employ a a greater amount of Thermoprene,and in some 1 cases even a smaller amount where increased .amounts of softenmg agents are employed.

Themineral rubbermay be replaced in who or in'part b-ygfother softeners for rubber,

ucl? soft t ine 'tch etc. .the follow- V V p Qbead 'W1re'25 n a-fabric strip 28 preferably :,ing.recipe having been found to beespecial- -lyfpr acticali Thermoprene 9 parts by; weight, ground vulcanized scrap 55 parts,

mineral rubber 9 parts,-soft tar 6 parts, Dixie clay 15,,parts, rubber preservative, 1 part, [sulfur 1.5 partsand calcium oxide 5 parts.

7 Referring to the drawing, I show in Figs.

. 1 to 4 the successive steps employed in carry- 1 ing out one embodiment of my invention. A

, thermoplastic bead composition 10 of the -character. 1 described in the preceding para I graphs, is banked upon specially embossed" hot rolls 111 and 12 of a calendar, which derlive'rsa beadbody 13 of continuous length,v Y preferably of across section-shown in Figa 2. Thebead-body 13 is hot and consequently soft as it leaves the calender and may be passed through a cold waterbath 14 1101500].

. r-the bead-and an air? drier .15 to remove the surfacefilmiof'wateradhering thereto. The bead is then passed. through a cement, as in the bath 16, preferably a solution-of Thermoprenein anorganic solvent, such as benzol, gasoline, etc., and then through another air,

dryer .17'which evaporates the solvent from J the cement. fThe-bead maynovw bev wound, ihelically. upon a cylinder v18, cut onan element of the cylinder, the. lengths' spliced 'as by a tape winding 19, and the flipper 20 applied, the latter s tepsbeingperformed in the usual manner.

Certain variations may bemade'in the process just outlined. A tubing machine may replace the calender. Where presses for ouring beads are already installed, as in plants equipped for the old process of fabricating beads, the bead may be compacted and shaped by pressing for '2 minutes at 7 Opounds steam. This is by nomeans" an essential step but gives'to the head a smoother'and cleaner-cut appearance, Furtherdthc flipper maybe applied'to thebead beare uaing and forming into rings and the flipper maybe a rubberized fabric,or a sheetedflhermopreneystock similar to the bead body but preferablycontaining aminor proportionof fiber. I

\Vhere inextensible wire beads are to be formed, the braided orstranded wire25 (see Figseto is covered ina tubing machine, I or 'otherwise,-with a coating" or insulation 26 1 of a vulcanizable Thermioprene'fcomposition of the character employed for forming the It 35 'beadbody of-Fig's l to '4, and formed into a 'ring oftwo or more'convolutions. \Vhere 'the insulated wire braid "is to bestoredin fricti'oned with, Thermoprene or rubber, as;

shown i11 Figs.6, 7 and 8, which fabric wrapf ped bead maybe shaped in a mold] Ifthe' head is stored atthis stage of its manufad ture, its adhesive character may be restored by dipping in asolvent, such". as 'gasoline, or-ina' thin Thermoprene cement, and a fiipper29 appliedin the usual manner. As

shown in Fig.10, the fabric, wrap 28 and the flipper 29 may be replaced by a sheet 30 of a Therinoprene bead-body" composition, in which fibers may have been mixedto give it-" added strength.

A further modification of the wire bead is illustrated in Figs. 11,12, and 13,in which a Thermoprenebead stock containing fibers is 'calendered or tubedto form a filler -por-" tion 81 and a wrapperportion 32. The surfaces to be folded in are coated with a Ther moprene cement and the 'Wire'braid 25 oovered by folding the wrapping portion 32 about the filler portion 31, as indicated in the drawing.,

In all of the processes above described the economy effected in the numberof'operations required to make the bead and in the time re-L quired for similar operations, incomparison with the prior practice in constructing beads is very material, and the resulting bead has in addition the advantage of simplicity of construction. x V 'tunder tire building conditions,'incorporat-.

ing in the carcass of the the the unvulcanized bead, and thereafter simultaneously vulcanizing the vulcanizable portions of the bead and carcass.

2. In the process of manufacturing a pneumatic tire casing having a bead member constructed to include a body portion of vulcanized composition, and a fabric covering of the flipper type, the steps which comprise shaping the body portion of the bead from a vulcanizable but unvulcanized composition which consists at least in part of Thermoprene and which is plastic at somewhat elevated temperatures but which possesses at normal temperatures a sufficient degree of hardness and strength to retain its shape under tire building conditions, incorporating in the carcass of the tire the unvulcanized bead, and thereafter simultaneously vulcanizing the vulcanizable portions of the bead and carcass.

3. In the process of manufacturing a pneumatic tire casing having a bead member including a body portion of a vulcanized composition with a metallic reenforcement therein, the steps which comprise covering the metallic reenforcement with a vulcanizable but unvulcanized composition which consists at least in part of Thermoprene and which is plastic at somewhat elevated temperatures but which possesses at normal temperatures a sufficient degree of hardness and strength to retain its shape under tire building conditions, shaping the covered metallic reenforcement into an endless bead body, incorporating in the carcass of the tire the unvulcanized bead, and thereafter simultaneously vulcan izing the vulcanizable portions of the bead and carcass.

4. In the process of manufacturing apneumatic tire casing having a bead member including a body portion of a vulcanized composition with a circumferential wire reenforcement therein, the steps which comprise covering the wire with a vulcanizable but unvulcanized composition which consists at least in part of Thermoprene and which is plastic at somewhat elevated temperatures but which possesses at normal temperatures a suificient degree of hardness and strength to retain its shape under tire building conditions, assembling a plurality of convolutions of the covered wire into an endless bead body,

incorporating in the carcass of the tire the unvulcanized bead, and thereafter simultaneously vulcanizing the vulcanizable portions of the bead and carcass.

5. In the process of manufacturing a pneumatic tire casing. having a bead member in cluding a'body portion of a vulcanized composition with a circumferential wire reenforcement therein, the steps which comprise covering the wire with a vulcanizable but 1111- vulcanized composition which consists atv least in part of Thermoprene and which is. plastic at somewhat elevated temperatures but which possesses at normal temperatures a sufficient degree of hardness and strength to retain its shape under tire building conditions, assemblinga plurality of convolutions of the covered wire into an endless bead body, applying a flipper strip to the bead body, in-

corporating in the carcass of the tire the unvulcanized bead, and thereafter simultaneously vulcanizing the. vulcanizabl'e portions of I the bead and carcass.

In witness whereof I have hereunto set my hand this 11th day of June, 1925.

WILLIAM C. GEER. 

